Isotope effect in collision between heliumatom and hydrogen bromide molecule

The anisotropic potential developed in our previous research and theclose-coupling method are applied to the HBr--$^{3}$He ($^{4}$He,$^{5}$He, $^{6}$He, $^{7}$He) system, and the partial cross sections(PCSs) at the incident energy of 60,meV are calculated. Based onthe calculations, the influences of the isotope helium atom on PCSsare discussed in detail. The results show that the excitation PCSsconverge faster than the elastic PCSs for the collision energy andthe systems considered here. Also the excitation PCSs converge morerapidly for the high-excited states. The tail effect is present onlyin elastic scattering and low-excited states but not in high-excitedstates. With the increase of reduced mass of the collision system,the converging speed of the elastic and excitation PCSs slows down,and the tail effect goes up.